Mineralization of phenazopyridine, 1, in water, under solar-simulator radiation was efﬁciently achieved using nanoparticle CdS-sensitized rutile TiO2 , TiO2 /CdS, 2, as photo-catalysts. Despite that, 2 showed two main drawbacks. Firstly, the system was difﬁcult to recover by simple ﬁltration, and demanded centrifugation. Secondly, the sensitizer CdS showed relatively high tendency to leach out hazardous Cd2+ ions under photo-degradation reaction conditions. In an attempt to solve out such difﬁculties, 2 was supported onto sand surface. The sand/TiO2 /CdS system, 3, was easier to recover but showed slightly lower catalytic activity compared to 2. On the other hand, the support failed to prevent leaching of Cd2+ . This indicates limited future applicability of CdS-sensitized TiO2 photo-catalyst systems, in solar-based water puriﬁcation strategies, unless leaching out tendency is completely prevented.